Term preferred to conc. by Haydn, Mozart, and others, for comp. for more than one solo instr. and orch., e.g. Mozart's for vn. and va. In 20th cent. Walton, Williamson, and others have used the term even where only one solo instr. is employed, to imply that solo part is more closely integrated with orch. than in a ‘display’ conc.